Hi everyone, I have an M320 I recently got working and being that it is not the M320b I don’t have phantom power. What’s the best way to add it? Is it as simple as buying an external power supply my condensers and is there anything that needs to be upgraded in the console itself? Or is there anyway to add it internally and install a button on each channel? Thank you!
Tascam M320 phantom power question
- Thread starter Sav2319
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bouldersoundguy
Well-known member
Yes, it's as simple as buying an external phantom power supply. It will also take another XLR.
sweetbeats
Reel deep thoughts...
So my first question is how many condenser mics do you need to power? If it is just a couple, I would 100% just get an external phantom supply. Don’t hack up your M-320. You could totally do it. I think you can get the M-300B manual supplement pdf online somewhere, and the info for the phantom circuit with it. It’s simple enough…but it would be a decent amount of work to incorporate on a non-B model. I don’t think the non-B main transformer has the secondary taps to power a 48V regulated supply. So it’d be easiest to just get a used open-frame modular supply, like a Power One or Lambda supply…and then you’d need a bunch of DPST switches, the output of the phantom supply daisy chains through one side of the switches, and the two poles of the other side of the switches each connect to pins 2 & 3 of an XLR jack, each leg through a bias resistor…Teac spec’ed 6.8K for those. A lot of times you see a small value film cap in there too I think to deal with any DC spike when switching, but it’s not necessary.
Extremely helpful! I’d probably not be using more than 5 condensers at a time so I might not go through all the trouble if all I have to do is get an external unit, but this is the info I was looking for just out of curiosity! Thanks Sweetbeats
sweetbeats
Reel deep thoughts...
For sure. You’re welcome. 5 is a decent number of condensers. If you have funds to get external P48 supplies for them, then obviously that’s the easiest. Another in betweener option is to not worry about being able to individually switch each input on or off, and wire it up globally. You could just add the wires and bias resistors to, like, 8 of your mic input jacks, and add an XLR connector on the back of the console labeled phantom input, and get one single channel phantom supply to supply power globally to those 8 inputs. You can also do the same kind of thing and have a panel in your rack or even a box on the floor with XLR-F input jacks and XLR-M output jacks wired isolated each input to output, and then add your daisy chain phantom supply wiring to those, add a phantom input jack and connect a single channel external phantom supply to that mess; a dedicate external P48 distribution box. Then all your condensers would connect to the inputs of the distribution box, and the outputs connect to your mic inputs on the M-320. That’s another way to do it that’s cheaper than an off-the-shelf multi-channel P48 box, and easier to put together than modifying your Tascam. If you’re like me you have parts to do this laying around in stashes. My attic and garage are the audio parts equivalent of the guy that buries money in coffee cans in his back yard.
can't thank you enough for posting this schematic for the power supply circuit - lifesaver as I recap and restore this 312B I got here. Cheers,
If I might interject? That regulated supply has been the mainstay of perhaps millions of mixer and tape machine circuits for decades and it performs very well except for one serious failing. The slightest slip of a test probe causing a short and it is history. Do yourself a favour and use a modern chip regulator. The TL783C is, I am assured by D Self in his book Small Signal Audio Design very reliable, low ripple and bombproof.
Page 539 of the book also shows how to derive a 68V +ve rail from an existing 17-0-17V transformer supply using a tripler circuit and the aforementioned chip. Although this technique will not deliver the rated 10mA to many mic channels.
Dave.
Page 539 of the book also shows how to derive a 68V +ve rail from an existing 17-0-17V transformer supply using a tripler circuit and the aforementioned chip. Although this technique will not deliver the rated 10mA to many mic channels.
Dave.